The challenges presented by mechanical vibrations in rotating machinery are likely as old as rotating machinery itself. Vibrations of interest in rotating machinery can typically be classified as either torsional or transverse. Transverse vibrations in this context can be generally understood as oscillations about an equilibrium point that deflect a rotating element in directions transverse to the axis about which the element is rotating. Torsional vibrations are rotational oscillations circumferentially about the axis of rotation. If excessive vibrations are not addressed, mechanical fatigue and failure eventually tends to occur.
Various mechanisms are known for reducing or eliminating vibrations, either through dissipation of kinetic energy of vibrations to another energy form such as heat, or by absorbing kinetic energy from a vibrating system and then returning it to the system in a manner that is less disruptive to system operation or integrity. Certain strategies also seek to change the mass and vibrational characteristics of a given system so that harmonic excitation is less apt to occur during a typical duty cycle. Where multiple pieces of equipment are coupled together such as engines, transmissions, and driven loads such as pumps, compressors and the like, the multiple sources of rotation and reciprocation can produce complex vibrational phenomena that are difficult to even characterize, much less ameliorate. United States Patent Application Publication No. 2011/0085924 to Shampine et al. is entitled Pump Assembly Vibration Absorber System, and discloses one example of a resonant system applied to a pump assembly to counteract harmonic excitation therein.